DE102016104052A1 - Method and system for a laser pressure transducer - Google Patents

Abstract

Methods and systems are provided for accurately estimating intake or exhaust manifold pressure of an engine by means of a laser pressure transducer. A laser circuit is coupled to a pressure sensitive diaphragm mounted on the engine manifold. The manifold pressure is derived based on a deflection of the membrane as estimated based on a timing between emission of a laser pulse into the membrane and detection of a reflected pulse from the membrane.

Description

area

The present application relates to methods and systems for a laser pressure transducer coupled to an engine manifold for accurately and inexpensively measuring manifold pressures.

Background and abstract

Engine systems may include one or more pressure transducers at various locations for measuring engine operating parameters such as manifold pressure (MAP), exhaust pressure, boost pressure, air pressure, etc. The measured parameters are then used to control engine settings. For example, based on the measured parameters, the settings of the various engine actuators may be adjusted, such as the operation of an intake throttle, catalytic converter, turbocharger, particulate filter, etc. In addition, the measurements affect engine controls for exhaust emissions and engine fuel consumption. Various thruster designs are available, including, for example, piezoresistor type (PRT) encoders and capacitor type encoders. However, such transmitters may have a short lifetime due to the inhospitable environment in which they are located. This is especially true in the case of outlet pressure transmitters. For example, capacitor type encoders and PRT encoders may degrade due to their circuitry being exposed to corrosive liquids. Because the measurement provided by the encoders significantly affects engine control, such encoders may require frequent replacement to allow reliable measurements.

An example of an output transducer having improved performance is described by Goto et al. in US 8208143 provided. In this case, an exhaust gas sensor uses a glass fiber for irradiating exhaust gas with laser light, whereby the light radiates through the exhaust gas path. The light is measured by a detector after passing through the exhaust gas. Based on the light received by the detector, various emission parameters such as concentration, temperature, etc. are determined. In yet other examples, strain gauge pressure transducers whose resistance value varies with sensor deformation may be used.

The degree of deformation of the sensor is correlated with the pressure in the vicinity of the sensor.

However, the inventors of the present invention have recognized potential problems with such approaches. As an example, such transducers may still be prone to corrosion by exhaust gas components. For example, because the sensor substrate is coupled across a cross section of the exhaust passage, it may easily deteriorate due to contact with high temperature exhaust gas and corrosive exhaust gas components. As a result, the sensor may need to be replaced even if the laser is functional. Further, placement of the detector in the exhaust environment makes its view of the light source susceptible to soot obstruction. Consequently, there can still be expensive warranty issues. In addition, there may be a possibility of requiring a callback of an engine component that degrades a customer quality perception of the vehicle manufacturer. As another example, the sensors can be expensive. For example, strain gauge assemblies, when assembled in a sealed membrane, require severe cleaning of the mounting surface and require manual attachment of the strain gauge to the diaphragm with a bridge adhesive. Then the rest of the area may need to be filled with potting compound. The multiple steps increase the cost and complexity, which can make the sensor too expensive.

In one example, some of the above problems may be addressed by a method for an engine, comprising: adjusting engine operation in response to laser pulses bouncing off of a diaphragm in an engine manifold. In this way, a pressure sensor may be provided within a diaphragm which is deflected by pressure fluctuations in the engine manifold.

As an example, an engine manifold may be configured to include a laser pressure transducer system. The laser pressure transducer system may include a hollow diaphragm coupled to the engine manifold. For example, the diaphragm may be shaped to estimate intake manifold pressure in an engine intake manifold. As another example, the diaphragm may be mounted or embossed on an exhaust manifold to estimate exhaust manifold pressure. A diode laser and a laser detector may be attached to an upper surface of the membrane. For example, the laser and detector may be mounted to a housing that holds the diaphragm in the engine manifold. The internal cavity of the membrane may be sealed, reducing the need for frequent and thorough cleaning. The laser can be operated to inject laser pulses of a predetermined frequency into the interior (in Direction of the bottom) of the membrane. The pulses can then be reflected from the interior and bounce back up where they can be detected by the detector. Deformation of the membrane may be determined based on an elapsed time between emission of the laser pulse from the laser and detection of the reflected pulse at the detector. The elapsed time may be compared to a threshold duration that is learned under calibration conditions when it is known that the diaphragm has no deformation (such as during an engine off condition). As the elapsed time decreases relative to the calibrated threshold, the estimated deformation of the diaphragm may increase. Further, the strain estimate may be adjusted based on a temperature of the membrane as determined by a thermal sensor mounted adjacent the laser and the detector on the membrane. The thermal sensor may estimate the membrane temperature based on the detection of infrared radiation received from the interior of the membrane. The estimated deformation of the membrane may be correlated directly with a manifold pressure level experienced by the membrane. In some embodiments, the output of the laser, in addition to the static pressure measurement, may also be used to perform a Doppler shift analysis of the diaphragm displacement, thereby providing a higher resolution dynamic pressure measurement. One or more engine operating parameters such as throttle opening and boost pressure may then be adjusted based on the manifold pressure estimate. By using a laser pressure transducer, both the static pressure measurement and the dynamic pressure measurement can be achieved with the same pressure transducer. As such, the Doppler shift analysis of the manifold pressure may be outside the capabilities of conventional strain gauge pressure sensors.

In this way, a lower cost manifold pressure transducer / sensor can be provided without compromising the accuracy or reliability of the sensor. By using lasers, detectors, and thermal sensors coupled to a sealed membrane, the sensor circuitry can be protected from the inhospitable environment of the engine intake or exhaust manifold, which improves sensor durability and reduces warranty problems. By employing laser components that can be easily assembled (for example, a circuit that can be assembled with assembly machines on a single circuit board), the cost and complexity of mounting a pressure transducer into an engine intake or exhaust manifold can be reduced. By improving the reliability of the pressure measurement, engine control errors can be reduced.

It should be understood that the summary above is intended to introduce in simplified form a selection of concepts that are further described in the following detailed description. It is not intended to identify key features or essential features of the claimed subject matter whose scope is defined by the claims which follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any other part of this disclosure.

Brief description of the drawings

1 shows an exemplary internal combustion engine, which is formed with a laser pressure transducer system.

2 shows an exemplary embodiment of the laser pressure transducer system of 1 ,

3A - 3B show exemplary views of a laser pressure transducer system molded into an intake manifold.

4 shows an exemplary laser pressure transducer system mounted on an exhaust manifold.

5 FIG. 11 is a high-level flowchart for adjusting engine operation based on a manifold pressure estimate obtained via the laser pressure transducer system.

6 FIG. 10 shows an example embodiment of an engine system having individual particulate filters deployed in individual exhaust ports. FIG.

7 FIG. 11 is a high-level flow chart for identifying a deterioration of an engine component in the engine system of FIG

6 based on the manifold pressure determined by an exhaust laser transducer.

Precise description

Methods and systems are provided for a low cost and long lasting laser pressure transducer. The pressure transducer can be connected to the intake manifold or exhaust manifold of a Engine system such as the engine system of 1 and 6 to accurately estimate a manifold pressure (eg, intake or exhaust manifold pressure). The pressure transducer may be formed as a sealed membrane mounted with a circuit associated with each of a laser, a detector and a temperature sensor ( 2 ). The membrane may be molded into an intake manifold as shown in FIG 3 is shown, or embossed on an exhaust manifold, as it is in 4 is shown. An engine controller may be configured to execute a control routine such as the routine of 5 to emit laser pulses from the laser into the membrane and then to detect a reflected pulse at the detector, which bounces off the interior of the membrane. The manifold pressure may be correlated with a degree of deformation of the membrane, wherein the deformation is based on a time elapsed between the emission of the laser pulse and the detection of the reflected pulse. The controller may also be configured to execute a control routine such as the routine of 7 to identify degradation of an engine component (eg, a fuel injector or a single channel particulate filter or misfire event) based on the exhaust manifold pressure estimated by the laser pressure transducer. In this way, the manifold pressure can be accurately learned and at the same time the life of the manifold pressure sensor can be extended.

1 shows a schematic representation of a vehicle system 6 , The vehicle system 6 includes an engine system 8th , The engine system 8th can be an engine 10 that have several cylinders 30 comprising. The engine 10 includes an engine intake 23 and an engine exhaust 25 , The engine intake 23 includes a throttle 62 that with an engine intake manifold 44 via an inlet channel 42 is fluidically coupled. The engine exhaust 25 includes an exhaust manifold 48 which eventually becomes an outlet channel 35 leads the exhaust into the atmosphere.

In the example shown, the engine system 8th a turbocharged engine system with a turbocharger 50 Is provided. The turbocharger 50 includes an intake compressor 52 that about a wave 53 by turning an exhaust turbine 54 is driven. The throttle 62 can in the inlet channel 42 , the intake compressor 52 downstream and an (optional) aftercooler 56 upstream, be arranged. If provided, the aftercooler may be configured to reduce the temperature of intake air being compressed by the charging device.

The intake manifold 44 can be a laser pressure transducer 106 include, the throttle 62 and the aftercooler 56 downstream to determine an intake manifold pressure (MAP). As in 3 executed can the pressure transducer 106 be formed as part of the intake manifold (or an inlet pipe or an inlet chamber). As in 2 carried out, the laser pressure transducer may comprise a membrane, wherein the manifold pressure is determined based on the deformation of the membrane. The membrane may be made of the same material as the intake manifold, such as fiberglass. This improves the longevity of the sensor. An engine controller may adjust one or more engine operating parameters, such as charge level, throttle opening, and / or amount of exhaust gas recirculation, based on the estimated intake manifold pressure.

The engine exhaust 25 may be one or more emission control devices 70 which may be coupled into the outlet in a close coupled position. The one or more emission control devices may include a three-way catalyst, a lean NOx trap, an SCR catalyst, etc. Exhaust fumes after passing through the emission control device 70 can be treated via the outlet channel 35 be ejected into the atmosphere.

The exhaust manifold 48 can also be a laser pressure transducer 108 , the emission control device 70 upstream for determining an exhaust manifold pressure. In an alternative example, the laser pressure transducer may be in the exhaust manifold of the turbine 54 be arranged upstream in the straight region of the exhaust manifold. Such a placement would also provide detection of a blocked or missing emission control device 70 enable. As in 4 executed can the pressure transducer 108 on the exhaust duct 35 (or an outlet pipe or an outlet chamber) be embossed. As in 2 carried out, the laser pressure transducer may comprise a membrane, wherein the manifold pressure is determined based on the deformation of the membrane. The membrane can be made of steel or aluminum. This improves the longevity of the sensor in the inhospitable and corrosive environment of the exhaust manifold. An engine controller may adjust one or more engine operating parameters, such as charge level, throttle opening, and / or exhaust catalyst temperature, based on the estimated intake manifold pressure.

The vehicle system 6 can also have a tax system 14 contain. It is shown that control system 14 Information from multiple sensors 16 (a variety of examples of which are described here) and receives control signals to multiple actuators 81 (a variety of examples of which are described here). As an example, the sensors 16 an exhaust gas sensor 126 (located in the exhaust manifold 48 ), a temperature sensor 128 , the intake manifold pressure transducer 106 and the outlet pressure transducer 108 include. Other sensors such as additional pressure, temperature, air / fuel ratio, and composition sensors may be located at various locations in the vehicle system 6 be coupled. As another example, the actuators may be a fuel injector 66 , a throttle 62 , a store level output by the turbocharger 50 etc. include. The tax system 14 can a controller 12 include. The controller may receive input information from various sensors that process input information and trigger the actuators in response to the processed input information based on instructions or code programmed therein and corresponding to one or more routines. An exemplary routine is with reference to 5 shown.

With reference to 2 is an exemplary embodiment 200 a laser pressure transducer shown. The laser pressure transducer can be equipped with an intake manifold (such as a sensor 106 from 1 ) or with an exhaust manifold (such as a sensor 108 ). The encoder 200 includes a membrane 202 , In an example where the transmitter is coupled to an engine exhaust manifold, the diaphragm may 202 cast (or embossed or incorporated) into the exhaust manifold. In addition, the integrated membrane may be made of a material that is resistant to higher temperatures, such as aluminum or steel. In another example, where the transmitter is coupled to an engine intake manifold, the diaphragm may 202 be formed in the intake manifold, for example, as a flat location on the intake manifold. In addition, the integrated membrane may be made of the same material as the intake manifold, such as Flex (fiberglass). In other examples, the transmitter diaphragm may be made from a conventional transmitter housing having a plastic or metal diaphragm, and a sensor conduit (eg, a sensing sensor conduit) may be used.

A diode laser 204 and a laser detector 206 can each be on top of the membrane 202 be mounted and directed to an inner surface at the bottom of the membrane. In addition, a thermal sensor 208 be mounted on an upper side of the membrane and directed to an inner surface on the underside of the membrane. The optical components may alternatively be mounted to a housing that holds the diaphragm in the engine manifold. As such, the cost of lasers has dropped significantly in recent years due to the spread of diode laser technology into manufacturing products. In addition, the circuitry associated with the diode lasers and detectors can be easily mounted on a single circuit board with placement machines. As a result, the diode laser 204 , the detector 206 and the thermal sensor 208 lightweight and cost-efficient on the top of the membrane 202 be coupled. As such, this may reduce the cost and complexity of the laser thruster via strain gage assemblies requiring thorough cleaning of a mounting surface, manual attachment of a strain gauge to a membrane with adhesive, and careful filling of a cavity of the diaphragm with a potting compound.

The membrane 202 may be hollow, with the cavity sealed. The outer surface of the membrane may be deformable when pressure is applied. A load near the membrane 202 (as in the intake manifold or the exhaust manifold, based on the location of the encoder) may exert pressure on the diaphragm, thereby deforming it. In particular, when the manifold pressure increases, the deformation of the membrane may increase. The controller 12 may be configured to estimate the deformation of the membrane based on laser pulses received upon rebound of (the inside) of the membrane, and correlate the deformation of the membrane with a manifold pressure estimate. One or more engine operating parameters may then be adjusted based on the estimated manifold pressure, as in FIG 5 is executed.

The controller 12 can be designed to use the laser 204 to emit laser pulses into the interior of the membrane. In particular, the laser can 204 a laser pulse 210 emit in and towards a bottom of the membrane. The laser pulse 210 may be a lower power pulse. For example, the laser pulse used may pass through frequencies at low energy intensity. As an example, the laser may be frequency modulated with a repetitive linear frequency ramp. The detector 206 , which is located at the upper end of the membrane, may be a flyback pulse 212 received from the lower surface of the membrane is received. In particular, after the laser emission, light energy reflected from the membrane is passed through the detector 206 detected. By directing the laser and the detector on the inside of the membrane out of the sealed cavity of the membrane, both the laser and the optics of the laser and the detector can be kept clean become. As such, this allows for more accurate measurements while increasing the durability and life of the pressure transducer system.

The difference in time (ie the elapsed time) between the emission of the laser pulse 210 and the detection of the reflected pulse 212 can be used to estimate a degree of deformation of the membrane. The time difference may be further compared to a time threshold. Because, for example, the distance of the laser 204 to the lower surface of the membrane 202 is small, a detection of a reflected laser pulse by the detector 206 occur in the picosecond time domain. A time threshold based on the time required for a laser pulse to travel the length of an undeformed membrane back and forth (e.g., 1 picosecond) can therefore be taken as the reference value for comparison with the measured time difference. The reference value may be learned under selected conditions in which the diaphragm is not deformed, such as soon after diaphragm assembly in the manifold or during an engine off condition. If the detection of the reflected light energy requires less than 1 picosecond for an emitted laser pulse, this indicates membrane deformation. Thus, an estimated membrane strain may increase as the time required for the detection of the reflected pulse decreases from the threshold. Because membrane deformation is due to pressure exerted by the load in the manifold on the membrane, manifold pressure (MAP) can be deduced based on increased membrane deformation. In some examples, membrane deformation (and thus MAP) can be estimated by frequency modulation techniques using frequency modulated laser beams with a repetitive linear frequency ramp.

The pressure estimate may also be adjusted to compensate for changes in membrane strain due to temperature. In particular, the thermal sensor 208 be designed to a temperature of the membrane based on infrared radiation 214 attached to the thermal sensor 208 from the inside of the membrane 202 is appreciated, appreciated. As with reference to 5 For example, a controller may estimate the manifold pressure based on the estimated temperature and the estimated diaphragm displacement, respectively, by referring to a look-up table. If the estimated manifold pressure (MAP) is within a valid range (based on the length of the diaphragm), the MAP signal may be used to adjust engine operating parameters. Otherwise, the encoder output may be considered faulty and in a degraded range of accuracy.

It will be appreciated that in addition to the static pressure measurements discussed above, using the same laser pressure transducer, higher pressure dynamic pressure measurements may be performed while, however, a Doppler shift measurement of the estimated diaphragm displacement / strain is applied. Therein, by comparing membrane excursions at two different times and observing a Doppler shift between the excursions, a change in the MAP can be deduced. For example, the value of the two types of measurements may be compared, bearing in mind that the MAP must detect if a large static value is approaching which may damage the inlet.

With reference to 3A Figures 2-B are exemplary views of a laser pressure transducer system coupled to an intake manifold. Exactly shows 3A a top view 300 of the pressure transducer, which is connected to an intake manifold while 3B a side view 350 shows.

The top view 300 shows an intake manifold 302 that with the cylinder head 304 is connected and adapted to an intake air charge through channels 306 to deliver to engine cylinders (not shown). The intake manifold 302 consists of a heat-resistant material such. B. fiberglass plastic. The intake manifold may be with cross structures 307 be formed, which protrude beyond the plane of the intake manifold. The cross structures 307 provide structural stiffness to the intake manifold 302 ready. Between the cross structure 307 lie flat areas 308 ,

The intake manifold laser thruster 106 (from 1 ) can into the intake manifold 302 be shaped. Specifically, the membrane 310 in the shallow area 308 of the intake manifold 302 be shaped. In other words, one of the flat areas may be the pressure-sensitive membrane. The central location of the diaphragm allows it to deflect in proportion to the pressure in the center of the manifold, which is translated into an electrical output by the laser transmitter.

The membrane 310 may be made of the same material as the intake manifold, such as fiberglass. Laser circuit components 312 can then be placed on top of the membrane. In particular, the laser circuit components 312 on a laser circuit board 318 printed, which is housed on the top of the membrane. The laser circuit components 312 can use a diode laser (for emitting the laser pulses), a laser detector (for detecting the reflected laser pulses) and a thermal sensor (for receiving infrared radiation from inside the membrane).

The side view 350 from 3B shows the membrane 310 in the intake manifold 302 is shaped, and the laser housing 316 which is molded on top of the membrane. The membrane 310 is in the shallow area 308 of the intake manifold 302 shaped so that the manifold pressure of the air charge can be estimated at a location that the intake throttle 314 downstream and the channels 306 , which supply air to the cylinders, is downstream. The laser housing may be designed such that the laser circuit board 318 can slide into the housing. This reduces the cost and complexity of the laser pressure transducer system.

In one example, the membrane 310 a generally planar surface exposed to prevailing intake manifold pressure, wherein the laser circuit components 312 on an opposite side of the planar surface exposed to the intake manifold internal volume. The laser circuit components may include a laser that is vertically aligned at the back surface of the surface exposed to the interior volume of the intake manifold. The generally planar surface of the membrane 310 In general, it may be aligned with an inner surface of a wall of the intake manifold so that it is flush with the manifold wall so as not to protrude further into the inner cavity of the intake manifold than other portions of the intake manifold wall in the vicinity.

With reference to 4 is an exemplary embodiment 400 a laser pressure transducer system coupled to an exhaust manifold. An embodiment 400 shows an exhaust manifold 408 which is designed to exhaust gases during passage 70 be treated by the emission control device, via the exhaust duct 35 from the downstream to the atmosphere. The exhaust manifold 408 is made of a heat-resistant material such as fiberglass, plastic, steel or aluminum.

The exhaust manifold laser thruster 108 (from 1 ) can into the exhaust manifold 408 being shaped. More precisely, the membrane 410 in the outlet channel 35 being shaped. Alternatively, the membrane 410 as part of the basic structure of the exhaust manifold in a similar arrangement to that cast or machined described above with respect to the intake manifold laser pressure transducer having a flat portion of the exhaust manifold designed to be the pressure sensitive diaphragm. The integrated membrane 410 may be made of a refractory material including the same material as the exhaust manifold such as aluminum or steel (e.g. 304 Stainless steel) and / or plastic. Laser circuit components 412 can then be placed on top of the membrane. In particular, the laser circuit components 412 on a laser circuit board 418 printed on the top of the membrane in a housing 416 is housed. The laser circuit components 412 may comprise a diode laser (for emitting the laser pulses), a laser detector (for detecting the reflected laser pulses), and a thermal sensor (for receiving infrared radiation from inside the membrane). The laser housing may be designed such that the laser circuit board 418 can slide into the housing. Alternatively, the circuit board may be embossed in the housing. This reduces the cost and complexity of the laser pressure transducer system.

It will be understood that in alternative embodiments, the intake manifold and / or the exhaust manifold laser pressure transducer system may include a conventional encoder housing having a plastic or metal diaphragm and a sensor conduit connecting the laser circuit board components to the diaphragm.

With reference to 5 is an exemplary process 500 for operating the laser pressure transducer system to estimate a manifold pressure and adjust an engine operating parameter based on the estimated manifold pressure. The method enables engine operation to be adjusted in response to laser pulses received after rebounding from a diaphragm in an engine manifold.

at 502 can be confirmed that the laser of the laser thruster is turned on and sends pulses (or is able to send pulses). If not, the laser may be on 503 turned off. In addition, an error status can be sent to the PCM controller. For example, a diagnostic code may be set by the engine controller to indicate a faulty laser transducer.

When the laser works, the procedure includes 504 operating the laser to emit laser pulses to an interior of the membrane. The laser may be mounted or embossed on top of the membrane, and therefore may be configured to direct the emitted laser pulses toward an interior of the membrane, and in particular to a bottom surface of the membrane. To the For example, the laser pulses may be emitted from a laser mounted on the diaphragm toward a diaphragm coupled to an engine manifold. The laser pulses may be emitted synchronously with an engine spark frequency. at 506 The method comprises detecting laser pulses reflected from the bottom surface of the membrane at the detector mounted or imprinted on top of the membrane. In particular, laser pulses reflected from an interior of the diaphragm to an interior of the manifold may be received at a detector mounted to the diaphragm.

at 508 The method includes confirming that the laser detector receives a distance signal in a valid range. As such, the elapsed time between the emission of the laser pulse and the detection of the reflected pulse correlates with a distance between the top of the membrane (where the laser pulse is emitted) and the bottom of the membrane (where the laser pulse is reflected). If the distance signal received at the detector is greater than a signal corresponding to the length of the membrane, it can be determined that the detector does not receive a distance signal in a valid range. If the signal is not in the valid range, then the method returns 503 back with the laser turned off and an error status displayed.

If the laser detector receives a distance signal in a valid range, then the method includes 510 confirming that the thermal sensor (also mounted on top of the diaphragm) reads in a valid temperature signal (Td). For example, an expected temperature of the diaphragm may be determined based on engine operating conditions. If the thermal sensor reading is higher or lower than the expected reading by more than a threshold amount, it may be determined that the thermal sensor output is inaccurate. If the reading of the thermal sensor is invalid, then the procedure at 512 setting a diagnostic code to indicate that the thermal sensor is degraded. For example, a temperature error status for deteriorated accuracy may be set. In addition, the membrane temperature can be set to a standard temperature (eg 60 ° F).

Next, the method involves 514 calculating a distance to the diaphragm (Dmeas) based on the elapsed time between the emission of the laser pulse and the detection of the laser pulse. For example, the distance may be determined by frequency modulation techniques using frequency modulated laser beams with a repetitive linear frequency ramp.

at 516 The method includes estimating an amount of membrane deformation (or displacement) based on the laser pulse timing relative to a threshold. As such, the membrane may be molded into the manifold (or stamped or cast into the manifold). Thus, based on an amount of pressure experienced by the diaphragm in the engine manifold (which may be an intake or exhaust manifold), the deformation of the diaphragm may vary. In particular, the deformation of the diaphragm may become larger as the manifold pressure increases, and accordingly, the distance to the diaphragm (as well as the time elapsed between the emission of the laser pulse and the detection of the reflected pulse) may decrease. In one example, the estimated time difference between the emission of the laser pulse and the detection of the laser pulse may be compared with a time difference estimated under a calibration condition when the diaphragm is not deformed, such as when the engine is not operating. Alternatively, a distance to the diaphragm estimated during engine operating conditions may be compared to a threshold distance to the diaphragm estimated under calibration conditions when the diaphragm is not deformed. In addition, as the estimated time difference decreases from the threshold, an estimated deformation of the diaphragm due to the manifold pressure may increase. Also, as the estimated distance to the diaphragm decreases, the deformation of the diaphragm may increase due to the manifold pressure.

at 518 the manifold pressure can be estimated based on the deformation of the membrane. The manifold pressure estimate may also be adjusted based on the estimated temperature of the diaphragm (Td). For example, at a given temperature, as the deformation of the diaphragm increases, an estimate of the manifold pressure applied to the diaphragm may increase accordingly. The controller may resort to a look-up table stored as a function of the distance to the diaphragm (or laser timing) and the diaphragm temperature to determine the corresponding manifold pressure (MAP).

at 520 can be determined whether the manifold pressure is within a valid range. For example, an expected manifold pressure may be determined based on engine operating conditions. If the estimated manifold pressure is higher or lower than the expected pressure by more than a threshold amount, it may be determined that the pressure signal is invalid. If at 524 it is determined that the pressure signal is invalid, the method includes determining an error status for degraded range accuracy (eg, by setting a diagnostic code). In addition, the estimated (invalid) pressure may be stored in the memory of the controller, but not used to adjust engine operating parameters.

If at 522 determining that the pressure signal is valid, the method includes determining a status for a valid pressure. In addition, the estimated (valid) pressure can be stored in the memory of the controller. at 526 For example, one or more engine operating parameters may be adjusted based on the estimated manifold pressure. For example, the adjusting may include adjusting an intake throttle opening, adjusting a charge level, adjusting an amount of exhaust gas recirculation, and / or adjusting an exhaust catalyst temperature in response to the estimated manifold pressure.

In still other embodiments, the exhaust manifold pressure estimated by a laser pressure transducer coupled to the exhaust manifold may be shared with engine ignition and position timing data to provide fuel injectors for an engine system having individual particulate filters (eg, gasoline particulate filters or GPF). diagnosed in individual outlet channels. An example of such an engine system is with reference to 6 provided. An exemplary method for indicating engine misfire and / or fuel injector degradation in response to the laser pulses received after rebound from a diaphragm in an engine manifold is described with reference to FIG 7 shown.

6 shows a schematic representation of an example of an internal combustion engine 600 with individual particle filters 664A -D in exhaust ducts 662A -D of cylinders 648A -D the engine 600 , The present arrangement of the engine 600 is shown with four cylinders. However, an engine with a different arrangement (for example, with more or fewer cylinders) may be used. Furthermore, the engine can 600 an example of the engine system in some embodiments 8th from 1 be.

As in 6 shown includes the engine 600 an engine intake manifold 620 with an air intake passage 622 that turns into an air filter 624 leads. A gas flow control device (eg, an intake throttle 626 ) can the air filter 624 be arranged downstream to increase the air flow rate to an engine block 640 to regulate. As an example, the intake throttle 626 during pedaling, an open throttle and a closed throttle during a pedal release. Intake air can be at the throttle 626 over and into a compressor 627 of a turbocharger. Compressed intake air may pass through an engine intake passage 630 to engine cylinder air intake valves 642A -D flow. As an example, the engine cylinder air intake valves 642A -D the gas flow to the engine cylinders 648A -D on the basis of an engine speed, an engine load and / or an AFR.

Exhaust gas recirculation (EGR) may be from an EGR conduit 670 through an EGR inlet control valve 680 in an engine EGR intake passage 632 and engine cylinder EGR intake valves 644A -D flow. As can be seen in the present embodiment, the engine air intake passage is 630 separate from the engine EGR intake passage 632 and the two gases can not mix before reaching their respective engine cylinder valves. However, in other embodiments, the two gases may mix and flow into a single passage leading to a control valve that controls a gas intake into an engine cylinder. Although a high-pressure EGR system (HD-EGR system) is shown (for example, where exhaust from one point, that of the turbine 629 upstream of the turbocharger, via the EGR line 670 to an inlet passage of the compressor 627 it is important to note that additional or alternative EGR arrangements in the engine 600 may be included. For example, an LP EGR system (eg, where exhaust gas from a location that is the turbine 629 downstream of an inlet passage leading to the compressor 627 upstream) flows in some examples in the engine 600 be included.

The engine cylinders 648A -D in an engine block 640 are arranged receive fuel from each fuel injectors 646A -D. exhaust ports 662A -D are each at a first end with the engine cylinders 648A -D coupled and connect at a second end 660 to an exhaust manifold passage 666 as part of the exhaust manifold. Exhaust from the exhaust manifold 660 optionally flows through the EGR line 670 and / or the turbine 629 , Exhaust gas flowing through the turbine 629 is then sent to one or more exhaust aftertreatment devices, such as a three-way catalyst (TWC). 672 delivered. In typical exhaust systems, a single, large particulate filter may be located downstream of a TWC. As in 2 Each of the individual particle filters can be shown 664A -D in another of the outlet channels 662A -D the engine cylinder 648A -D be arranged. Therefore, exhaust gas flowing out of a first cylinder flows only through a first particulate filter (for example, exhaust gas flows out of the cylinder 648A only through the particle filter 664A ). In other words, a particulate filter only receives exhaust gases from a single cylinder (eg, the particulate filter receives 664A Exhaust only from the cylinder 648A ). In this way, the plurality of individual particulate filters, which may be smaller than particulate filters included in typical exhaust systems, may be in the engine 600 instead of the single, large particulate filter typically present in other vehicles downstream of the TWC. It goes without saying that the individual particle filters used in the engine 600 may be included in other examples in addition to a single, large particulate filter behind the TWC. The particle filter 664A D may comprise suitable material for capturing and / or removing particles from the exhaust gas passing through the filters.

A single laser outlet pressure transmitter 668 can be downstream of each of the exhaust ducts and the turbine 629 be arranged upstream. However, it will be understood that other arrangements of aftertreatment devices, turbines, and exhaust pressure sensors may be used in other examples of the engine 600 may be included. For example, individual laser pressure transmitters in each outlet channel 662A -D the TWC 672 and the turbine 629 upstream and inside the exhaust manifold 660 each particle filter (for example 664A D) be arranged downstream. The exhaust gas from the exhaust passages of the cylinders becomes in the exhaust manifold 660 merged. The exhaust gas from each exhaust passage may be either to the EGR passage 670 or to the TWC 672 stream. The EGR line 670 directs exhaust gas toward the EGR inlet control valve 680 , The TWC 672 converts harmful exhaust gas compounds into more harmless compounds before the exhaust gas is released into the atmosphere.

In this arrangement, the outlet laser pressure transducer 668 a pressure of the exhaust gas in the exhaust manifold 660 measure up. The pressure sensor 668 may determine the pressure of the exhaust gas originating from a single engine cylinder (eg, exhaust gas flowing out of the cylinder through the associated exhaust passage to the exhaust manifold) based on a combustion time. The firing time may be correlated with a single cylinder firing event to assign pressure measurements to the single cylinder firing event. The frequency at which the pressure sensor signal is sampled may be a selected frequency and may be timed to correspond to individual cylinder firing events. In one example, the pressure sensor signal may be sampled each time the controller receives a firing profile acquisition (PIP) signal. The PIP signal may be from a crankshaft sensor such as the Hall effect sensor 120 from 1 each time a tooth (or missing tooth) of a wheel coupled to the crankshaft passes the Hall effect sensor. Since the crankshaft position is correlated with each individual cylinder firing event, the position may be used to determine which single cylinder firing event corresponds to the pressure sensor signal measurement in the sweep sensed at that crankshaft position.

The single cylinder exhaust pressure measurement provides information to fuel injectors 646A -D to diagnose, such as misfire events (as in 7 ) and a high particle load in the particle filters 664A -D. Further, the exhaust pressure measurement may be used to diagnose cylinder air / fuel imbalances during shifts. When the pressure sensor 668 For example, if it is determined that the exhaust pressure amplitude for a single cylinder is higher than an expected exhaust pressure prior to an ignition event for the cylinder, then it may be determined that the cylinder has misfired. As another example, if the pressure sensor 668 if the outlet pressure amplitude for a single cylinder is below an expected outlet pressure amplitude and / or an average outlet pressure amplitude, it is determined that the particulate load of the single particulate filter for that cylinder is higher than an expected and / or acceptable particulate load. Thus, a controller may be based on the measurement from the pressure sensor 668 command a regeneration of the single particulate filter in response to the high particulate load diagnosis on that particulate filter.

In the example described above, the expected exhaust pressure may be based on engine operating conditions, such as engine speed and spark timing, spark timing, or a predetermined value determined as a function of engine parameters, such as air mass. Likewise, the average exhaust pressure may be an average measurement of the exhaust pressure amplitudes associated with the respective cylinder over a particular period of time (eg, a selected number of engine cycles).

As another example, in response to a measurement of the exhaust pressure amplitude for a cylinder being below a threshold, it may be indicated that a fuel injector associated with the cylinder (eg, the fuel injector, the fuel in FIG injecting this cylinder) is degraded. In response to such determination of a degraded fuel injector, engine adjustment may be commanded to account for the effects of the degraded fuel injector (eg, the increased particulate load on the particulate filter resulting from the increased particulate output due to the degraded fuel injector). In some embodiments, the engine adaptation may include delaying the ignition timing to increase the cylinder temperature to regenerate the particulate filter and / or clean the fuel injection device of deposits.

With reference to 7 is an exemplary process 700 for identifying a deterioration of a fuel injector, deterioration of a single channel particulate filter, and / or a misfire based on an exhaust manifold pressure estimated by an exhaust laser pressure transducer. Although the method with respect to the engine system of 6 It will be appreciated that the method may be similarly applied to other engine system arrangements.

at 702 The method includes retrieving engine firing and position timing data. This includes retrieving data relating to the timing of the firing events in each engine cylinder and the position of a piston in each cylinder. In other words, it can be determined what stroke each cylinder is in, and whether or not an ignition event has occurred in a particular engine cylinder.

at 704 The method includes estimating an exhaust manifold pressure based on laser pulses coming from an interior of a membrane of an exhaust laser pressure transducer (such as the transducer 108 from 1 or the sensor 668 from 6 ) bounce off. As with reference to 5 For example, measuring the exhaust manifold pressure may include emitting a laser pulse from the diode laser mounted on the membrane into the interior of the membrane and then detecting a laser pulse reflected from the interior of the membrane at a detector also on the detector Membrane is mounted, include. A distance from the laser to the diaphragm is then estimated based on a time elapsed between the emission of the laser pulse and the detection of the reflected pulse. The distance is compared to a threshold to determine the amount of deflection or deformation of the membrane resulting from the manifold pressure exerting a force on the diaphragm. A manifold pressure estimate is then calculated based on the distance (or displacement). The manifold pressure estimation is further based on a temperature of the membrane as estimated by a thermal sensor mounted on the membrane, the thermal sensor receiving infrared radiation from inside the membrane.

The measuring of the outlet pressure may include: taking a sample of the outlet pressure measurement timed for each cylinder. In one example, it may be timed for each exhaust stroke of the cylinder. Thus, each sample may include one or more pressure pulses associated with exhaust output from a particular cylinder. As such, the exhaust pressure measurements estimated by the laser pressure transducer may be continuously detected (eg, such that an uninterrupted signal is output from the exhaust pressure sensor during operation, where the sample is a selected portion of the signal output from the sensor) only be detected during the sampling time. The exhaust pressure profile (eg, the amplitudes of the pressure pulses in an exhaust pressure amplitude measurement scan) may be associated with a single cylinder based on the comparison of the sampling time and / or the time at which the pressure pulses occurred relative to an ignition timing for each cylinder. Since the exhaust pressure pulses (eg, the peak values in an exhaust pressure sensor signal) may occur due to exhaust from a single cylinder entering the exhaust manifold during the exhaust stroke of that cylinder, exhaust pressure measurement taken at a selected time may be associated with the individual cylinder. which causes the outlet pressure pulse at the time.

at 706 The method includes comparing the generated / estimated exhaust pressure profile to an expected pressure profile including exhaust pressure peak profiles for each cylinder. The expected profile may be based on engine operating conditions including the firing order of each cylinder. In alternative examples, the estimated outlet pressure profile (eg, the amplitude of the outlet pressure peaks) may be compared to a threshold. The threshold may be based on an expected outlet pressure amplitude and may include a guard band (eg, a range of outlet pressure values, where the highest outlet pressure value is the top edge of the guard band and the lowest outlet pressure value is the bottom edge of the guard band).

at 708 For example, it may be determined whether the measured outlet pressure profile is equal to (or within a threshold distance of) the expected outlet pressure profile. If yes, then the procedure includes 710 indicating that there is no deterioration of the fuel injectors or particulate filters (injected into the channels). In addition, it can be stated that there is no misfire.

If there is a deviation between the measured profile and the expected profile, then the controller can 712 identify fuel injector degradation, particulate filter deterioration and / or misfire event based on the deviation of the measured profile from the expected profile. For example, the controller may be at 713 indicate a misfire event based on the measured exhaust pressure for a single cylinder being much lower than an expected exhaust pressure (eg, more than a threshold difference lower than the expected exhaust pressure) for the given cylinder after a firing event for the given cylinder. In this way, when the manifold pressure estimated by the laser transducer is an exhaust pressure, a controller may indicate a cylinder misfire based on the estimated manifold pressure and further based on a cylinder firing timing.

As another example, the controller may be included 714 indicate a fuel injector degradation based on the measured exhaust pressure for a given cylinder, which is lower than a threshold due to the reduced supply of fuel to the cylinder. In this way, when the manifold pressure estimated by the supercharger pressure transducer is an exhaust pressure, a controller may indicate a degradation of a cylinder fuel injector based on the estimated manifold pressure relative to an engine firing timing.

As yet another example, the controller may be included 715 indicate particulate filter degradation based on the measured outlet pressure for a given cylinder being lower than the corresponding expected outlet pressure.

In this way, degradation of one or more engine components (including the identity of a cylinder in which the component is degraded) may be based on a manifold pressure estimated by a laser transducer and further based on an amplitude of the estimated manifold pressure relative to Cylinder piston positions (indicating what stroke the cylinder is in) and a cylinder firing timing (indicating when a cylinder firing event occurs) are identified.

For example, a controller may be configured to perform a method for an engine, comprising: emitting laser pulses into a diaphragm coupled to an engine manifold, from a laser mounted on the diaphragm; Receiving laser pulses after reflection from an interior of the membrane to a detector mounted to the membrane; Estimating a distance to the membrane based on a duration that has elapsed between the emitting and the receiving; and adjusting engine operation based on the estimated distance. The method may further include receiving infrared radiation from the interior of the membrane at a thermal sensor mounted on the membrane and estimating a temperature of the membrane based on the received infrared radiation. Here, the adjusting includes estimating a manifold pressure based on the estimated distance and further based on the estimated temperature of the diaphragm and adjusting the engine operation based on the estimated manifold pressure, wherein the estimated manifold pressure at a given temperature increases as the estimated distance to the diaphragm increases. The laser, detector and thermal sensor are each mounted at the top of the membrane and the emitted laser pulses are emitted from the top of the membrane into the interior of the membrane, while the reflected pulses from a bottom of the membrane to the detector at the top of the membrane Membrane to be reflected. The distance to the membrane may include a distance from the laser to the underside of the membrane. The method may further include indicating cylinder misfire based on the estimated manifold pressure and further based on cylinder firing timing.

In another example, a vehicle system includes an engine comprising: an exhaust manifold; a diaphragm molded into the exhaust manifold, wherein an upper surface of the diaphragm is coupled to the exhaust manifold and an underside of the diaphragm is disposed in an exhaust passage of the exhaust manifold; a diode laser and a laser detector mounted on top of the diaphragm; a thermal sensor mounted at the top of the membrane for detecting infrared radiation within the membrane; and a controller. The controller may be provided with computer readable instructions stored on a nonvolatile memory to operate the laser for: emitting laser pulses to an interior of the membrane; Detecting laser pulses coming from the bottom of the diaphragm be reflected at the detector; and estimating a manifold pressure based on a duration that elapses between emitting a laser pulse and detecting a reflected pulse. Further, the controller may be configured to adjust an engine operating parameter based on the estimated manifold pressure. The engine may further include an intake throttle and a turbocharger such that the adjusting includes increasing an opening of the intake throttle and / or increasing an output of the turbocharger when the estimated manifold pressure falls below a threshold. The elapsed time between emitting the laser pulse and detecting the reflected pulse may be a first duration estimated under an engine running condition, and the controller may further include instructions for: comparing the first duration to a threshold, wherein the threshold is at a threshold second duration, which has elapsed between the emission of the laser pulse and the detection of the reflected pulse under an engine calibration condition, wherein the diaphragm is not deformed at all under the engine calibration condition. In other words, the second duration is used as a reference. The controller may include other commands for estimating a temperature of the membrane based on an output of the thermal sensor, wherein the estimated manifold pressure is adjusted based on the output of the thermal sensor.

It should be understood that although the laser pressure transducer discussed above is shown as an engine intake manifold (intake or exhaust) manifold, this is not intended to be limiting and the laser pressure transducer may also be used in alternative locations for pressure sensing. For example, in an alternative illustration, the laser pressure transducer may be coupled to an engine cylinder to estimate in-cylinder pressure. In this case, a steel lining may comprise a membrane surface above a piston path zone. The laser circuit housing may then be mounted on the back of the piston path zone. A controller may adjust engine operation in response to laser pulses received after rebound from a diaphragm coupled to the cylinder (eg, coupled into the cylinder). The membrane may be cast or embossed within the cylinder above a piston travel zone. As an example, an engine controller may be configured to emit laser pulses into a diaphragm coupled to an inside of an engine cylinder from a laser mounted on the diaphragm; Receiving, after reflection, laser pulses from an interior of the membrane to a detector mounted to the membrane; Estimating a deformation of the membrane based on a duration that has elapsed between the emitting and the receiving; and estimating an in-cylinder pressure based on the estimated deformation. In another illustration, a controller may determine a laser mounted on a laser transducer, the transducer having a diaphragm connected to a combustion chamber, defining a distance from the laser to a bottom surface of the diaphragm. The laser may emit a laser pulse into the interior (eg, bottom) of the membrane. A laser detector may also be coupled to the membrane and configured to detect a reflection of the emitted laser pulse after reflection from the interior of the membrane. Based on a time elapsed between the emission of the laser pulse and the detection of the laser pulse, a distance from the laser to the lower membrane surface can be estimated. An in-cylinder pressure may then be determined based on the estimated distance. The in-cylinder pressure may be further adjusted based on an in-cylinder temperature estimate. A thermal sensor may also be coupled to the membrane and may be configured to detect infrared radiation received from the interior of the membrane. An engine controller may estimate the in-cylinder pressure based on each of the estimated distance and the estimated in-cylinder temperature (eg, by referencing a look-up table). One or more engine operating parameters such as fueling (fueling amount or timing), spark timing, intake throttle opening, and boost pressure may then be adjusted based on the determined in-cylinder pressure.

It will be understood that in yet other illustrations, the laser pressure transmitter discussed above may be used for telemetering pressure remotely by means of the laser and thermal sensors on a controlled area of a pressure vessel. As such, this can be used to advantage to measure extremely hot or cold cylinders, such as in an atomic reactor. Remote sensing (including through a window) may allow pressure to be measured in areas where direct contact is impractical or impractical, such as on the outside of a supersonic vehicle or in a severe EMC environment.

To facilitate remote pressure measurement using a laser transducer, the transmitter system may include a laser, a detector and an IR sensor for remotely viewing a diaphragm from the outside of a pressure vessel. For a fixed distance and a fixed relative position, the laser structure of the same as the one discussed above with respect to the manifold pressure transducer. In this case, the diaphragm deflection can be assigned to a pressure of the pressure vessel. For a relative movement with a plane, for example for a moving body of the body with the diaphragm relative to the laser / detector, the laser can illuminate targets on the right and left edges of the diaphragm in the plane of movement and then their distance can be measured become. This may require two additional lasers. The average of the distances of the two targets can be used to create a "zero pressure" deflection of the membrane. The diaphragm displacement may then be determined as the measured diaphragm spacing minus the "zero pressure" displacement distance. The deflection is then assigned to the pressure.

For relative movement in three-dimensional space, such as for a moving location of the body with the diaphragm relative to the laser / detector, targets may be established at the right, left, top and bottom edges of the diaphragm, the selected targets being illuminated by the laser and their distances are measured. This may require up to four additional lasers. The average of the distances of the four targets can be used to create the "zero pressure" deflection of the membrane. The diaphragm displacement may then be determined as the measured diaphragm spacing minus the "zero pressure" displacement distance. The deflection is then assigned to the pressure.

In this way, the manifold pressure can be accurately and inexpensively estimated by employing a laser pressure transducer having a pressure sensitive membrane. Using a laser to correlate the deflection of a diaphragm coupled to an engine manifold with the manifold pressure, the reliability of manifold pressure estimation can be increased. By coupling the laser emitters and the detector to the sealed internal cavity of the membrane, the sensor circuit is protected.

In this way, a lower cost manifold pressure transducer / sensor can be provided without compromising the accuracy or reliability of the sensor. By using lasers, detectors, and thermal sensors coupled to a sealed membrane, contact of the sensor circuit with corrosive liquids and high temperatures can be reduced. Thus, the durability and durability of the pressure sensor improve, and at the same time, engine warranty problems associated with a degraded pressure sensor are reduced. By using a more reliable and more durable manifold pressure sensor for engine control, fuel economy and engine performance can be improved.

It should be appreciated that the example control and estimation routines included herein may be used with various engine and / or vehicle system arrangements. The control methods and routines disclosed herein may be stored as executable instructions in nonvolatile memory and may be executed by the control system that includes the controller in combination with the various sensors, actuators, and other engine hardware. The specific routines described herein may include one or more of any number of processing strategies, such as processing. As an event-driven strategy, an interrupt-driven strategy, multi-process operation, multi-strandedness and the like. Therefore, various operations, operations, and / or functions may be performed in the illustrated sequence or in parallel, or in some cases omitted. Likewise, the processing order is not necessarily required to achieve the features and advantages of the embodiments described herein, but is merely for ease of illustration and description. One or more of the illustrated acts, operations and / or functions may be repeatedly performed depending on the particular strategy used. Further, the described acts, operations, and / or functions may graphically represent code to be programmed into a nonvolatile memory of the computer readable storage medium in the engine control system, wherein the described operations are accomplished by executing the instructions in a system employing various hardware components in combination with the system electronic controller includes.

It should be understood that the configurations and routines disclosed herein are exemplary, and that these specific embodiments are not to be construed in a limiting sense as numerous variations are possible. The above technology is applicable to, for example, V6, I4, I6, I3, V12, Boxer 4, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various systems and configurations and other features, functions, and / or properties disclosed herein.

The following claims particularly highlight certain combinations and sub-combinations that are believed to be novel and not obvious. These claims relate possibly to "an" element or "first" element or its equivalent. Such claims are to be understood to include the inclusion of one or more of these elements, neither requiring nor excluding two or more of these elements. Other combinations and sub-combinations of the disclosed features, functions, elements and / or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether their scope is further, narrower, equal, or different with respect to the original claims, are also considered to be within the scope of the present disclosure.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 8208143 [0003]

Claims (20)

Method for an engine, comprising: Adjusting engine operation in response to laser pulses received after rebounding from a diaphragm in an engine manifold. The method of claim 1, wherein the engine manifold is an intake manifold or an exhaust manifold. The method of claim 2, wherein the membrane is molded into the intake manifold. The method of claim 2, wherein the membrane is embossed in an exhaust passage of the exhaust manifold. The method of claim 1, wherein the laser pulses are emitted by a laser into an interior of the membrane and wherein the laser pulses are received at a detector after reflection at the interior of the membrane, the laser and the detector being respectively mounted to the membrane and wherein the Laser pulses are emitted synchronously with an engine ignition frequency. The method of claim 5, further comprising estimating a temperature of the membrane in response to infrared radiation received from within the membrane, wherein the infrared radiation is received at an infrared sensor coupled to the laser and mounted to the membrane , The method of claim 1, wherein the adjusting comprises estimating a deflection of the diaphragm based on the laser pulses, estimating a manifold pressure based on the displacement, and adjusting the engine operation in response to the estimated manifold pressure. The method of claim 7, wherein estimating the deflection of the membrane based on the laser pulse comprises comparing a time difference between emission of a laser pulse by the laser and detection of a reflected laser pulse by the detector with a time threshold and estimating the deflection based on the comparison includes. The method of claim 8, wherein the time threshold is based on a time difference between an emission of a laser pulse by the laser and a detection of a reflected laser pulse by the detector under a calibration condition under which the membrane is not deflected. The method of claim 9, wherein adjusting engine operation includes adjusting an intake throttle opening, adjusting a charge level, adjusting a fuel flow, adjusting an amount of exhaust gas recirculation, adjusting an ignition timing, adjusting a purge flow, adjusting the revolutions per minute, and /. or adjusting an exhaust catalyst temperature in response to the estimated manifold pressure. The method of claim 7, wherein the manifold pressure is an exhaust pressure and wherein the method further comprises indicating deterioration of a cylinder fuel injection device based on the estimated manifold pressure relative to an engine firing timing. Method for an engine, comprising: Emitting laser pulses toward a diaphragm coupled to an engine manifold from a laser mounted on the diaphragm; Receiving laser pulses reflected from an interior of the membrane opposite an interior of the manifold to a detector mounted to the membrane; Adjusting an engine operation based on a duration that has elapsed between the emitting and the receiving. The method of claim 12, further comprising: estimating a distance to the membrane based on a duration that has elapsed between emitting and receiving, receiving infrared radiation from within the membrane at a thermal sensor mounted on the membrane and estimating a temperature of the membrane based on the received infrared radiation. 14. The method of claim 13, wherein the adjusting comprises estimating a manifold pressure based on the estimated distance and further based on the estimated temperature of the diaphragm and adjusting engine operation based on the estimated manifold pressure, wherein the estimated manifold pressure increases as the estimated distance of the diaphragm increases at a given temperature. The method of claim 12 wherein the laser, detector and thermal sensor are each mounted to the top of the membrane, the emitted laser pulses being emitted from the top of the membrane into the interior of the membrane and the reflected pulses from a bottom of the membrane the detector is reflected at the top of the membrane and where the distance to the membrane comprises a distance from the laser to the underside of the membrane. The method of claim 12, further comprising: indicating a cylinder misfire event based on the estimated manifold pressure and further based on a cylinder firing timing. A vehicle system comprising: an engine comprising an exhaust manifold; a diaphragm molded into the exhaust manifold, wherein an upper surface of the diaphragm is coupled to the exhaust manifold and an underside of the diaphragm is disposed in an exhaust passage of the exhaust manifold; a diode laser and a laser detector mounted on top of the diaphragm; a thermal sensor mounted at the top of the membrane for detecting infrared radiation within the membrane; and a controller equipped with computer-readable commands for: Operating the laser to emit laser pulses to an interior of the membrane; Detecting laser pulses reflected from the underside of the membrane at the detector; and Estimating a manifold pressure based on a duration that elapses between emitting a laser pulse and detecting a reflected pulse; and Adjusting an engine operating parameter based on the estimated manifold pressure. The system of claim 17, wherein the engine further comprises an intake throttle and a turbocharger and wherein the adjusting comprises increasing an opening of the intake throttle and / or increasing an output of the turbocharger when the estimated manifold pressure falls below a threshold. The system of claim 17, wherein the elapsed time between emitting the laser pulse and detecting the reflected pulse is a first duration estimated under an engine running condition, and the controller further comprises instructions for: comparing the first duration to a threshold, wherein the threshold is based on a second duration that elapses between emitting the laser pulse and detecting the reflected pulse under an engine calibration condition, wherein the diaphragm is not deformed at all under the engine calibration condition. The system of claim 19, wherein the controller further comprises instructions for: estimating a temperature of the membrane based on an output of the thermal sensor, wherein the estimated manifold pressure is adjusted based on the output of the thermal sensor.

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